Question

1-calculate the mass of 4 moles of Na

2-what is the mass of 0.3 moles of water H2o H:1 O:16
3-compute the number of moles found in 10g of ethanol C2H5OH C:12 O:16


please help me as fast you can

Answer 1

1. 92 g

2. 5.4 g

3. 0.217 moles

Further explanation

The mole is the number of particles(molecules, atoms, ions) contained in a substance

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

`\tt n=(m)/(MW)`

1. the mass of 4 moles of Na(MW= 23 g/mol)

`\tt mass=mol* MW\\\\mass=4* 23\\\\mass=92~g`

2. the mass of 0.3 moles of water(MW=18 g/mol)

`\tt mass=mol* MW\\\\mass=0.3* 18\\\\mass=5.4~g`

3. the number of moles found in 10g of ethanol C2H5OH(MW=46 g/mol) :

`\tt mol=(10)/(46)\\\\mol=0.217`